Such a plug connector is known from DE 694 04 891 T2. In this known implementation, all differently-polarized conductors are surrounded by a design unit both within the plug body and within the engaging part. In contrast to what is shown in the named document, plug connectors of such type may also be three-poled or more, whereby the plug body and the engaging part for each of these versions represent a suitably-dimensioned design unit and thus require an individual housing for each. One might resort to the option of using two or more bi-polar plug connectors for a higher number of variously-polarized, mutually short-circuiting conductors.